Tony Stark is used to loneliness. His father wouldn't exactly win 'Dad of the Year' and his mother was barely home, and when she was she was barely sober enough to remember who she was, never mind her son.

When he goes to MIT he is still lonely, the arrogant son-of-a-billionaire (and something else as well), but he's got Rhodey now so it's not so bad, even though his parents are dead and Obadiah is too busy running the company.

By the time he's twenty five he's got Rhodey, Pepper, Obadiah and Happy and he's never been so lucky.

At thirty six he has the Avengers, he thinks. He's read the files - they will be working together as a team. So it doesn't matter that he's pushed Rhodey away and Pepper exchanges fond glances with Happy and Obadiah - there's no need to explain that.

And when the Avengers leave he doesn't say anything.

He's used to it.